Electronic devices, such as microprocessors, microcontrollers, input/output devices, and memory devices, have become increasingly powerful. For optimal performance, such devices operate at high clock speeds. Increased operating speeds lead to increased power usage by devices which in turn means that a greater amount of heat is generated by such devices during operation. A heat dissipation mechanism is typically used to prevent excessive heat buildup in the devices, which may damage the devices or reduce their reliability. Operational integrity can also be adversely affected when a device is overheated.
Computing and other electronic systems, including portable systems such as laptop or notebook computers or personal digital assistants, have continued to decrease in size. The relatively small size of such systems places a limit on the size and weight of heat dissipation components, such as heat sinks. Typically, components that have high power usage require larger heat-sinks for effective cooling in systems that employ forced air-cooling technology. However, system size limitations prevent use of large heat sinks.
Also, large heat sinks tend to be relatively heavy. When mounted directly on components, heavy heat sinks can cause reliability problems. For example, certain types of integrated circuit (IC) packages are easily damaged by the pressure and torque applied by a heavy heat sink both during static operating conditions and during transit conditions (e.g., during shipping), where shock and vibration may be induced. Further, a heavy heat sink can damage the connection between a component and a board on which the component is mounted. Various constraints thus serve to limit the size of heat dissipation components and potentially the effectiveness of such heat dissipation components.
In some systems, remote cooling is performed in which heat pipes are used to transfer heat from an IC device to a heat sink that is remotely located from the IC device. In such an arrangement, the heat sink is not directly mounted on the IC device, which allows flexibility in the size and shape of the heat sink.
Traditionally, the thermal connection between a heat pipe and an IC device surface is made by employing a thermally conductive metal block or heat spreader between the heat sink and the IC device. A heat pipe generally has an effective (or apparent) thermal conductivity that is several orders of magnitude greater than the thermal conductivity of most metallic heat spreaders. As a result, the use of a heat spreader in such an arrangement adds thermal resistance in the thermal path (due to the limited thermal conductivity of a conventional heat spreader or compared to the effective thermal conductivity of a heat pipe), which reduces the effectiveness of remote cooling of the IC device.
In general, a mechanism is provided to enhance heat dissipation in a system. For example, a system includes a device that generates heat during operation, with the device having a surface. The system further includes a heat spreader that is thermally contacted to the surface, with the heat spreader adapted to dissipate heat using a phase-change mechanism. A heat conduit is in thermal communication with the heat spreader to transfer heat from the heat spreader to another location in the system.
Other or alternative features will become apparent from the following description, from the drawings, and from the claims.